British diplomats will be allowed to attend the murder trial of Chinese politician Bo Xilai's wife, who stands accused of killing British businessman Neil Heywood. The move is being treated as an unusual concession by China.

Heywood, who had lived in China for 10 years, was found dead last November in a hotel in the south-western city of Chongqing, where Bo was the former Communist party leader. Bo was later ousted amid a scandal triggered by the death.

Chinese authorities at first blamed the death on excessive alcohol consumption but later accused Bo's wife, Gu Kailai, and an aide of poisoning the 41-year-old Briton.

Diplomatic sources said it was unusual for China to allow British diplomats to attend such a sensitive hearing, particularly when no UK citizen was on trial.

The British Foreign Office said last month: "We are dedicated to seeking justice for Neil Heywood and his family and we will be following developments closely."

Bo has been suspended from top party bodies. His wife theoretically faces execution if convicted of murder.

Chinese authorities announced last month that Gu and Zhang Xiaojun, a family employee, had been charged with "intentional homicide".

The Chinese state news agency, Xinhua, said the police investigation showed that Gu and her son had has business conflicts with Heywood.

Bo, who was once tipped to rise to the politburo standing committee – China top political body – had been suspended from the politburo for unspecified but serious violations of discipline. He had already been removed from his post as Chongqing party secretary.

Heywood is thought to have become close to Bo and his wife after he helped smooth the way for their son Bo Guagua's schooling at Harrow, Heywood's alma mater. Bo Guagua is now living in the US after graduating from his Harvard masters course this year.